95 results about "P-chloronitrobenzene" patented technology

The invention discloses a catalyst for synthesizing parachloroaniline by parachloronitrobenzene through hydrogenation and a preparation method thereof. The active component of the catalyst is Pt, the carrier is attapulgite, and the content of the Pt is 0.1-5wt%. The catalyst not only has high activity, but also effectively inhibits the generation of a dechlorination reaction. Under the condition that the parachloronitrobenzene is completely transformed, the selectivity of 100% for the parachloroaniline is realized.

The invention firstly provides a catalyst for catalyzing selective hydrogenation of a chloro nitro-compound. The catalyst is a Pt / TiO2 / SBA-15 catalyst or a Pt / ZrO2 / SBA-15 catalyst, and the content ofplatinum in the catalyst is 0.01-0.3 wt%, preferably 0.05-0.15 wt%, more preferably 0.08-0.10 wt%. The invention further correspondingly provides a preparation method of the catalyst and application of the catalyst in the reaction of selective hydrogenation of parachloronitrobenzene to prepare parachloroaniline. The catalyst shows excellent catalytic activity when used for catalyzing selective hydrogenation of parachloronitrobenzene to prepare parachloroaniline, the conversion rate and the selectivity are very high and both can reach up to 99% or above, and dechlorinating side reactions are greatly reduced. The preparation method of the composite nano-structure catalyst used in the method is simple, the production period is short, the platinum capacity is low, thus, the cost of the catalyst is low, and no reducing agent needs to be added during preparation. The dispersity of platinum is good, and catalytic activity is high.

The invention discloses a preparation method of 2-amino-5-chlorobenzophenone, comprising the following steps: (1) mixing ethanol with a mass concentration of 95%, sodium hydroxide, p-chloronitrobenzene and phenylacetonitrile, Stir, then ultrasonically oscillate at 25‑35°C for 1 h; (2) Microwave the product of step (1) for 10 min, add water to the system, filter, wash the filter residue 3 times with methanol, and then dry to obtain 5‑ Chlorine 3-phenyl-2,1-benzisoxazole; (3) Mix methanol, 5-chloro-3-phenyl-2,1-benzisoxazole, palladium-carbon catalyst, ammonium formate, heat and reflux for 2h, Cool to room temperature, filter, and vacuum-dry the filter residue. The method provided by the invention has high product yield, short reaction time, reduced waste discharge, and the production method is environmentally friendly.

The invention relates to the field of chemical production and particularly discloses a method and device for producing 3,4-dichloronitrobenzene through a continuous kettle type reaction. According to the method, parachloronitrobenzene serves as a raw material. The method is characterized in that parachloronitrobenzene and ferric trichloride are prepared into mixed liquor, the mixed liquor enters reaction kettles continuously through a nitro compound pump, and meanwhile chlorine enters the bottom of a chlorination kettle; under the catalyst effect, parachloronitrobenzene and chlorine react to generate 3,4-dichloronitrobenzene; later, by the utilization of the high-order difference among all the reaction kettles, the materials overflow sequentially to enter the reaction kettles connected in series, enter a storage tank finally, and then enter a static mixer through a mixing pump to be mixed with water, multiple washing kettles are connected in series, and qualified materials enter a crude product tank. The process is easy to operate, high in automatic control level, low in production cost, high in stability, safe to operate and suitable for large-scale industrial production, and effectively saves labor, and the purpose of continuously chlorinating and washing 3,4-dichloronitrobenzene is achieved.

The invention discloses a preparation method of sodium p-nitrophenolate. The preparation method comprises the following steps: a) heating and melting p-chloronitrobenzene in a melting kettle, and preparing a sodium hydroxide solution in a dissolving kettle; b) repeatedly introducing nitrogen into a system 3-6 times to replace air before a reaction, pumping the heated and molten p-chloronitrobenzene and the sodium hydroxide solution into a micro-reactor by using a feeding valve, uniformly mixing, and carrying out a high-temperature and high-pressure reaction; and c) transferring the solution after the reaction to a cooling crystallization kettle, and cooling to separate out a sodium p-nitrophenolate solid containing crystal water. According to the invention, a hydrolysis reaction is carriedout by adopting a micro-channel, so that the instant uniform mixing and the efficient heat transfer of the raw materials are realized while the equivalence ratio of the materials in the reaction process is reduced, the generation of side reactions and the difficulty in post-treatment are reduced, water can be recycled so as to reduce the energy consumption in production, improve the utilization rate of the raw materials and achieve the environment-friendly production process, the production cost is low, and the reaction time is greatly shortened; and the color of the prepared sodium p-nitrophenolate is faint yellow or orange yellow, and by-products are few.

The invention relates to a modification method for a raney nickel catalyst for p-chloronitrobenzene hydrogenation, and belongs to the technical field of organic synthesis. According to the method, a catalyst is added to deionized water containing 1-5% of a modifier, a stirring reaction is performed for 20-40 minutes at a temperature of 30-70 DEG C, and a standing treatment is performed for 30-90 minutes; a reduction agent with the concentration of 5-15% is added, a stirring reaction is performed for 30-60 minutes at the temperature of 40-50 DEG C, and NaHCO3 is adopted to adjust the pH value to 8-10, wherein a mass ratio of the reduction agent to the raney nickel catalyst is 4:1-8:1; a standing treatment is performed for 30-60 minutes, and deionized water is adopted to wash until the solution is neutral, a filtering treatment is performed, water is added, and sealed preservation is performed to prepare the modified raney nickel catalyst. According to the present invention, under the condition of no addition of the dechlorination inhibitor, the p-chloronitrobenzene conversion rate is more than or equal to 99.9%, the dechlorination side reaction generation rate in the p-chloronitrobenzene hydrogenation process is less than or equal to 2%, and the yield of p-chloroaniline is more than or equal to 95%; compared to the existing methods for preparing the hydrogenation catalyst, the method of the present invention has the following advantages that: the hydrogenation process is simplified, the three waste is less after the hydrogenation, the cost is low, the energy consumption is low, and the industrial requirements of quality increasing, consumption reducing, and environmental protection are achieved.

The invention relates to a synthesis method for co-producing p-chloroaniline and p-chlorophenol isocyanate. The method comprises the following steps of: reducing parachloronitrobenzene by using iron powder, separating water, dehydrating, adding a solvent, reacting with a bis(trichloromethyl) carbonate solution, distilling to recover the solvent, and distilling to obtain a p-chlorophenol isocyanate finished product. The method has the advantages that a process is advanced; process conditions are reasonable; the production of p-chloroaniline is organically combined with that of p-chlorophenol isocyanate; the environment pollution and an intoxicating phenomenon which are brought by p-chloroaniline used as an industrial product in the processes of aftertreatment, conveying, carrying and feeding can be avoided; virulent phosgene and diphosgene are avoided during production of p-chlorophenol isocyanate, and production is safe and reliable; the residual bis(trichloromethyl) carbonate is removed by normal-pressure reflux; the improvement on the quality of a product is facilitated; and the method has great implementation value and social and economic benefits.